Bing ads coupons are just for NEW accounts.
If you add coupons to an old account, you risk getting banned.
You can only add ONE coupon to a new account.
I even saw some courses that teach you how to get $1800 in coupon!
All bullshit, at the end you will get banned.
I quote here from their page http://advertise.bingads.microsoft.c...filiateprogram
|Get $50 in Bing Ads credits for signing up as a new Bing Ads customer. A new Bing Ads customer is one that has not advertised on Bing Ads before. The Bing Ads customer will receive a promotional code to redeem credits. Limit one (1) promotion code per new Bing Ads customer. Promotional code must be redeemed within thirty (30) days of Bing Ads new customer creation.|